Preheat the oven to 350℉ and grease a pie dish.In a medium bowl, combine the blueberries with the flour, sugar, corn starch, vanilla, lemon juice, and lemon zest. Pour into the pie dish.
To make the topping, combine the oats, flour, cinnamon, maple syrup, and butter. Mix with a wooden spoon until everything is well combined.Scatter the mixture over the top of the blueberries.
Place the crisp on a baking sheet and bake for about 40 minutes, until bubbling and golden. Cool for 5 minutes before serving.To serve: top with a scoop of full-fat Greek yogurt and a drizzle of honey or maple syrup.